Masters of different circular sizes are known in the prior art as is apparatus for exposing incrementally linearly variable lines on a photosensitive surface. U.S. Pat. No. 3,668,990 to L. P. Hayes, commonly assigned, is an example of such a device.
U.S. Pat. No. 3,695,154 to Webster relates to a photoexposure device for exposing lines on a photosensitive surface wherein the device has a rectangular aperture. The width of the light spot may be varied. A pair of blades sliding in perpendicular directions form a variable aperture to determine the size and shape of the light spot.
U.S. Pat. No. 3,688,655 to Klostermann et al relates to a method of, and an apparatus for, writing mask patterns on a photographic material by means of light. The boundaries of the slit through which the light passes control the length of the rectangular light spot.